Feadship, a prominent superyacht specialist from the Netherlands, has unveiled Project 821, the world's first hydrogen-fueled superyacht. With a length of 118.8 meters, this yacht marks a significant milestone in green technology in the marine sector. MAN Cryo has supplied a cutting-edge liquid-hydrogen gas-fuel system for Project 821, enabling zero-emission propulsion through a fuel cell system designed by PowerCell Group. This innovative system stores hydrogen in liquid form in a 92 cubic meter MAN Cryo fuel tank, allowing for sustainable and eco-friendly operation. The project represents a shift towards decarbonisation in the superyacht segment, showcasing Feadship's commitment to pushing the boundaries of green technology. Project 821's fuel-cell technology offers a week of silent operation at anchor and emissions-free navigation, emphasizing its sustainability. Additionally, the yacht is equipped with MTU generators combusting HVO biofuel for longer travels, ensuring a holistic approach to eco-conscious cruising. Despite facing challenges due to the lack of existing design codes for hydrogen storage, MAN Cryo, in collaboration with Lloyd's Register and Feadship, successfully developed a safe and approved tank design placed below deck. This groundbreaking achievement sets new standards for marine hydrogen projects and highlights the industry's progression towards sustainability. MAN Cryo's scope of supply for the project includes various innovative components such as a vacuum-insulated type C tank, a bunker station for shore-to-ship bunkering, and a tank prediction tool for efficient operations. The collaborative efforts of all stakeholders involved in the Project 821 have paved the way for future sustainable marine projects, positioning MAN Cryo as a frontrunner in marine fuel systems.